I think it would make your life a bit easier to just keep the casing, taking it off just ads more work. If you do take it off, then I suggest using a very strong glue.
gonna try a hose clamp, but since I have a topic, I just wanted to ask: what size tubing does the magstrike use, 1/4 in.? and if I wanted to buy a pump, as in something like an AT2K pump, where would I buy it and what would it be called?